A printed circuit board positioning device of a component mounter in the prior art is explained with reference to FIG. 29.
In the prior art, a reference positioning pin 52 with a diameter corresponding to the reference positioning hole 3 of each type of printed circuit board 2 is prepared in advance. A printed circuit board 2 is positioned on an XY table 1 by replacing the reference positioning pin 52 with one which matches the reference positioning hole 3 in the printed circuit board 2, and inserting the reference positioning pin 52 into the reference positioning hole 3.